JP5159254B2 - Image forming method - Google Patents

Description

  The present invention relates to toner used in an electrophotographic image forming method for developing an electrostatic charge image, toner used in a toner jet, an image forming method, and a process cartridge.

  In an electrophotographic apparatus, a process of forming a toner image on an image carrier and transferring the toner image on the image carrier to a transfer material such as paper is repeated on the image carrier without being transferred to the transfer material. It is necessary to remove the remaining toner. As a cleaning means for removing the toner remaining on the image carrier after the transfer, there are a fur brush and a blade, but a cleaning blade made of polyurethane rubber is mainly used from the viewpoint of productivity, cost, and performance. The cleaning blade is usually disposed in pressure contact with the running direction of the image carrier in the counter direction. When the frictional force between the image carrier and the cleaning blade becomes excessive, the edge of the cleaning blade may be reversed and the cleaning blade may bend.

  Normally, the area where toner is developed on the image carrier is in the image area (printable area), but a small amount of scattered toner adheres to the image carrier outside the development area (outside the toner coat area). There is. In order to reduce the adhesion of the scattered toner as much as possible, the charging area is wide at both ends outside the image area so that it is difficult to electrically attract the toner. However, even in such a configuration, it is difficult to eliminate toner adhesion. Therefore, it is necessary to sufficiently clean the cleaning blade in a sufficient range including the outside of the image area by making the longitudinal length of the cleaning blade sufficiently long.

  On the other hand, the amount of toner or external additive that reaches the cleaning blade is significantly smaller outside the image area than in the image area. The toner and the external additive have an effect of maintaining the lubricity between the cleaning blade and the image carrier, but the cleaning blade tends to chatter and squeeze outside the image area where the toner and the external additive are extremely small.

  Therefore, in order to reduce chattering and squeezing of the cleaning blade, the entire length of the cleaning blade is impregnated with an isocyanate compound (see Patent Document 1), and an attempt to coat a resin film on both ends of the cleaning blade (see Patent Document 2). ) Is also carried out.

  On the other hand, as a recent technical direction of an image forming apparatus, in addition to high definition, high quality, and high image quality, further high speed and long-term high reliability are required. In order to achieve a high-resolution and high-definition development system, development of toners having high development characteristics such as a reduction in toner particle size, sharpening of particle size distribution, and addition of a surface modification process are in progress. In particular, as one of shape control techniques for improving toner transfer efficiency, dot reproducibility, and the like, the shape of toner has been made close to a sphere in recent years. However, a toner that has a smaller particle size and a spherical shape compared to conventional toners requires a system that controls cleaning suitable for the powder characteristics.

JP 2001-75451 A JP2002-162885

  An object of the present invention is to provide a toner capable of maintaining good cleaning performance even for a long-term use in a high-speed development process and suppressing slipping through, toner leakage, cleaning blades and chatter.

  Another object of the present invention is to provide an image forming method using the above toner.

  Another object of the present invention is to provide a process cartridge having the above toner.

The present invention includes a charging step of charging an image carrier with a charging member, an electrostatic latent image forming step of forming an electrostatic image on the charged image carrier, and developing the electrostatic image with toner on a developing member. A developing step for forming a toner image, a transfer step for transferring the toner image formed on the image carrier onto a recording medium, and a surface of the image carrier after the transfer is brought into contact with a cleaning blade to bring the edge An image forming method comprising at least a cleaning step of removing transfer residual toner remaining on the image carrier from the image carrier,
The measurement value of the hardness by the micro rubber hardness tester at both ends in the longitudinal direction of the tip surface of the cleaning blade is 72 ° or more and 90 ° or less, the hardness of the entire side surface, and the hardness of the center portion in the longitudinal direction of the tip surface is 55 ° or more and 70 °. And
The toner has toner particles containing at least a binder resin and a colorant, and inorganic fine particles, and has the following formulas (1) and (2):
600 (mJ) ≦ E ≦ 1500 (mJ) (1)
500 (mJ) ≦ (E−Ea) (2)
(In the formulas (1) and (2), E (mJ) vertically enters the toner powder layer in the container while rotating the peripheral speed of the outermost edge of the propeller blade at 100 mm / sec. The measurement starts from a position 100 mm from the bottom surface of the toner powder layer, and represents the sum of the rotational torque and the vertical load obtained when entering the position 10 mm from the bottom surface. Ea (mJ) is porous at the bottom of the container. (This represents the sum of the rotational torque and the vertical load in a ventilation state in which dry air with a flow rate of 0.20 mm / sec is sent from a material board.)
It is related with the image forming method characterized by satisfying.

  According to the present invention, it is possible to suppress toner leakage from the end portion of the cleaning blade and chattering / snarling of the cleaning blade while maintaining the cleaning property.

The present inventors include a charging step of charging the image carrier with a charging member, an electrostatic latent image forming step of forming an electrostatic image on the charged image carrier, and a toner on the developing member. A developing process for forming a toner image by developing the toner image, a transfer process for transferring the toner image formed on the image carrier onto a recording medium, and a surface of the image carrier after the transfer is brought into contact with a cleaning blade The toner used in the image forming method having at least a cleaning step of removing the transfer residual toner remaining on the image carrier by the edge portion from the image carrier,
The measurement value of the hardness by the micro rubber hardness tester at both ends in the longitudinal direction of the tip surface of the cleaning blade is 72 ° or more and 90 ° or less, the hardness of the entire side surface, and the hardness of the center portion in the longitudinal direction of the tip surface is 55 ° or more and 70 °. And
The toner has toner particles containing at least a binder resin and a colorant, and inorganic fine particles, and has the following formulas (1) and (2):
600 (mJ) ≦ E ≦ 1500 (mJ)
(Preferably 800 (mJ) ≦ E ≦ 1200 (mJ)) (1)
500 (mJ) ≦ (E-Ea)
(Preferably 700 (mJ) ≦ (E-Ea)) (2)
(In the formulas (1) and (2), E (mJ) vertically enters the toner powder layer in the container while rotating the peripheral speed of the outermost edge of the propeller blade at 100 mm / sec. This represents the sum of rotational torque and vertical load obtained when measurement starts from a position 100 mm from the bottom surface of the toner powder layer and enters a position 10 mm from the bottom surface, and Ea (mJ) is porous at the bottom of the container. (This represents the sum of the rotational torque and the vertical load in a ventilation state in which dry air with a flow rate of 0.20 mm / sec is sent from a material board.)
It has been found that the object of the present invention can be achieved if the toner is characterized by satisfying the above.

  In the present invention, the powder characteristics of the toner are measured by using a powder fluidity analyzer, powder rheometer FT-4 (manufactured by Freeman Technology) (hereinafter sometimes abbreviated as FT-4). did. There are various conventionally known measuring methods for evaluating powder characteristics, and in particular, fluidity. For example, a powder tester (manufactured by Hosokawa Micron) can measure the angle of repose, the degree of compression, the spatula angle, the degree of uniformity, the degree of aggregation, and the like. However, these measurement results have not been able to evaluate the fluidity of the powder in the static state and the dynamic state under the same conditions. For this reason, in some cases, sufficient knowledge cannot be obtained to evaluate the behavior of a toner in the case where the toner in a stationary state is given fluidity as in the present invention.

The FT-4 used in the measurement of the present invention can obtain information on the rotational torque and vertical load applied to each of the toners in the states (i) to (iii) below.
(I) Toner when receiving force from outside in a stationary state.
(Ii) A toner in a state where fluidity is continuously maintained.
(Iii) A toner that changes from a state in which fluidity is maintained to a stationary state.

  In particular, toner used in a large-capacity and high-speed image forming apparatus requires stable cleaning properties for long-term use. Therefore, in addition to the configuration of the cleaning blade, toner fluidity control is also an effective means. Conceivable.

<Measurement method of E, Ea, Ed>
In the present invention, E (mJ), Ea (mJ), and Ed (mJ) are measured by a fluidity measurement method using a rotary blade. As the measuring device, for example, a powder fluidity analyzer, powder rheometer FT-4 (manufactured by Freeman Technology) (hereinafter sometimes referred to as “FT-4”) may be used.

  The device moves the blades through the powder sample, causing a constant flow measurement and pattern flow. The particles in the sample flow when the blade is in close proximity, and after passing, the blade falls and then rests again. The energy required for the blade to move through the powder is calculated, and from this value the various fluidity indices are calculated. Since the blade is a propeller type and moves in the upward or downward direction at the same time as rotating, the tip draws a spiral. The angle and speed of the spiral path of the blade can be adjusted by changing the rotational speed and the vertical movement. When the blade moves along a clockwise spiral path with respect to the powder layer surface, there is an action of mixing the powder uniformly. Conversely, when the blade moves along a counterclockwise spiral path with respect to the powder layer surface, the blade receives resistance from the powder.

  Specifically, the measurement is performed by the following operation. In all operations, the propeller type blade is a 48 mm diameter blade dedicated to FT-4 measurement (Fig. 1 There is a rotation axis in the normal direction at the center of the 48 mm x 10 mm blade plate. It is smoothly twisted counterclockwise such that the portion (24 mm from the rotating shaft) is 70 ° and the portion 12 mm from the rotating shaft is 35 °, and the material is made of SUS.Model number: C210. May be omitted).

  First, a FT-4 measurement dedicated 50mm x 160ml split container (model number: C203, 82mm height from the bottom of the container to the split part. The material is glass, hereinafter may be abbreviated as container) at 23 ° C, 60% environment. The toner powder layer is formed by adding 150 g of toner left for 3 days or more.

(1) Conditioning operation (a): The rotational speed of the blade (peripheral speed of the outermost edge of the blade) is 60 (mm / sec), the approach speed in the vertical direction to the powder layer is the outermost edge of the moving blade The angle between the locus drawn by the part and the surface of the powder layer (hereinafter sometimes referred to as “the angle formed”) is 5 (deg) at a speed of 5 (deg) and clockwise with the rotation of the blade. The blade is advanced from the surface of the powder layer to the position of 10 mm from the bottom surface of the toner powder layer in the rotation direction (the direction in which the powder layer is uniformly mixed).

  Thereafter, the blade rotation speed is 60 (mm / sec), the vertical approach speed to the powder layer is 2 (deg), and the rotation angle is clockwise with respect to the powder layer surface. Then, the blade is advanced from the bottom surface of the toner powder layer to a position of 1 mm.

  Thereafter, the toner powder is rotated clockwise with respect to the surface of the powder layer at a rotation speed of the blade of 60 (mm / sec) and an angle forming the extraction speed from the powder layer of 5 (deg). The blade is moved to a position of 100 mm from the bottom of the layer and extracted.

  When the extraction is completed, the toner attached to the blade is wiped off by rotating the blade alternately in small clockwise and counterclockwise directions.

  (B): The series of operations (1) to (a) are performed five times in total to remove the air entrained in the toner powder layer, thereby forming a stable toner powder layer.

(2) Split operation A toner powder layer having the same volume is formed by scraping the toner powder layer at the split portion of the above-described cell dedicated to FT-4 measurement and removing the toner on the powder layer.

(3) Measurement operation (i): Measurement of E (mJ) (a): The same operation as (1)-(a) above is performed once.

  (B): Next, the rotational speed of the blade is 100 (mm / sec), the vertical approach speed to the powder layer is an angle of 5 (deg), and counterclockwise with respect to the powder layer surface. The blade is caused to enter a position 10 mm from the bottom surface of the toner powder layer in a rotating direction (a direction in which resistance is received from the powder layer by rotation of the blade).

  Thereafter, the blade rotation speed is 60 (mm / sec), the vertical approach speed to the powder layer is 2 (deg), and the rotation angle is clockwise with respect to the powder layer surface. Then, the blade is advanced from the bottom of the powder layer to a position of 1 mm.

  Thereafter, the rotation speed of the blade is 60 (mm / sec), the angle forming the vertical extraction speed from the powder layer is 5 (deg), and in the clockwise rotation direction with respect to the powder layer surface, The blade is extracted from the bottom surface of the powder layer to a position of 100 mm.

  When the extraction is completed, the toner attached to the blade is wiped off by rotating the blade alternately in small clockwise and counterclockwise directions.

  (C): The series of operations in (b) above is repeated seven times.

  In the above operation (c), it is obtained when the blade enters the position from 100 mm to 10 mm from the bottom surface of the toner powder layer when the rotation speed of the seventh blade is 100 (mm / sec). Let E be the sum of rotational torque and vertical load.

(Ii): Measurement of Ea (mJ) FT-4 measurement-dedicated 50 mm × 200 ml container (model number: C200 and C620 (aeration bottom plate), height: 100 mm, material: glass, hereinafter abbreviated as aeration container) ) Is put into a toner powder layer by adding 150 g of toner left at 23 ° C. and 60% environment for 3 days or more.
(A): Toner powder for which measurement of E (mJ) has been completed is put into an aeration container, and the above operations (1) to (a) are performed once.
(B): Next, dry air is gradually aerated from the porous plate at the bottom of the container so that the flow rate becomes 0.20 (mm / sec). At this time, a dedicated ventilation unit for FT-4 measurement is used.
(C) The above operations (i) to (b) are performed once in a state where dry air has become familiar to the toner.
(D): Toner powder in a state where dry air having a flow rate of 0.20 (mm / sec) is passed after the operation of (c) and the rotational speed of the blade is 100 (mm / sec). Let Ea (mJ) be the total of the rotational torque and the vertical load obtained when the blade enters from the bottom surface of the layer to a position of 100 mm to 10 mm.

(Iii): Measurement of Ed (mJ) (a): After the operations of (ii)-(d), the supply of dry air is stopped, and at the same time, the operations of (i)-(b) are continued. The rotation obtained when the blade enters from the surface of the toner powder layer to the position of 10 mm from the bottom surface when the rotation speed of the blade at the fourth time is 100 (mm / sec). The sum of the torque and the vertical load is Ed (mJ).

  When a cleaning blade is used as the cleaning means, it is common to arrange the edge so as to face the moving direction of the image carrier (counter method), and this arrangement is convenient for toner cleaning. However, on the other hand, the friction between the image carrier and the cleaning blade is inevitably increased. As a result, the cleaning blade may chatter or sag. The chattering of the cleaning blade is a vibration of the blade due to an increase in frictional resistance with the image carrier, and the wrinkle is a phenomenon in which the blade is inverted and warped in the moving direction of the image carrier. In particular, when chattering occurs at the end of the blade where the frictional force with the image carrier is large, there is a possibility that the transfer residual toner at the end cannot be sufficiently cleaned or the blade is squeezed. In the present invention, a hardened layer is formed on the surface of the blade end portion where the frictional force with the image carrier is large, so that the frictional force between the cleaning blade surface and the image carrier is reduced, and chattering and wobbling can be suppressed. became.

  If the frictional force between the blade end and the image carrier is reduced, the cleaning force for the transfer residual toner normally supplied to the blade end tends to be weak, and toner leakage may occur from the end. However, by using a toner having fluidity such as the toner of the present invention, both the prevention of chattering and wobbling of the cleaning blade and reliable cleaning properties can be achieved, and toner leakage is less likely to occur.

  In the case of 600 (mJ) ≦ E ≦ 1500 (mJ) (preferably 800 (mJ) ≦ E ≦ 1200 (mJ)), the force applied when the toner is in a stationary state, that is, when the toner is loosened from a dense state in a deaerated state. Is large. In this case, the untransferred toner on the image carrier is easily peeled off from the image carrier because it is in a state of being easily subjected to drag from the blade.

  In the case of 600 (mJ)> E, the force applied when loosening the transfer residual toner on the image carrier is small. For this reason, since the fluidity of the toner is very high particularly when cleaning at the end of the blade, a cleaning failure is liable to occur, or the toner is scattered and toner leakage is likely to occur.

  When 1500 (mJ) <E, the force applied when loosening the transfer residual toner on the image carrier is very large. Therefore, a part of the transfer residual toner on the image carrier may remain without being peeled off, resulting in a cleaning failure.

  When 500 (mJ) ≦ (E−Ea) (preferably 700 (mJ) ≦ (E−Ea)), there is a large difference between the torque applied when the toner is loosened and the torque applied when the toner recovers fluidity. Show. This is because the transfer residual toner once peeled off from the image carrier has high fluidity in the process of being transferred into the cleaning container and is likely to diffuse smoothly into the cleaning container.

  When 500 (mJ)> (E−Ea), it is indicated that the difference between the torque applied when the toner is loosened and the torque applied when the toner recovers the fluidity is small. This is because the transfer residual toner once peeled off from the image carrier is in a state where it is difficult to recover the fluidity, and therefore, the transfer residual toner is difficult to be transferred to the cleaning container particularly at the blade end where the cleaning power is weak. Then, the transfer residual toner is likely to accumulate at the contact portion between the blade and the image carrier, and toner leakage may occur.

The toner of the present invention is
0.10 ≦ (Ed / E) ≦ 0.70 (preferably 0.30 ≦ (Ed / E) ≦ 0.60)
(Ed (mJ) is a rotational speed obtained by the same measurement as the above E (mJ) after stopping the ventilation from the state where the dry air whose flow rate is controlled is sent into the powder phase of the toner in the container. Represents the sum of torque and vertical load.)
It is further preferable in order to obtain the effects of the present invention.

  In the case of 0.10 ≦ (Ed / E) ≦ 0.70 (preferably 0.30 ≦ (Ed / E) ≦ 0.60), the toner that has been cleaned by recovering the fluidity smoothly flows into the cleaning container. Can spread.

  In the case of 0.10> (Ed / E), the toner whose fluidity has been recovered indicates that it can easily maintain fluidity even when the external force is lost. This is because the cleaned toner may be easily scattered around in the process of moving to the cleaning container in order to maintain high fluidity.

  When (Ed / E)> 0.70, it is indicated that the toner whose fluidity has been recovered easily loses its fluidity when the external force is lost. This is because the cleaned toner loses its fluidity immediately, and may not be smoothly transferred to the cleaning container, and toner leakage may occur.

  An outline of the configuration and operation of the image forming apparatus used in the present invention will be described.

  FIG. 2 is a schematic configuration diagram of the image forming apparatus of the present embodiment. The image forming apparatus according to the present exemplary embodiment is an electrophotographic type and a process cartridge detachable laser printer.

  Reference numeral 1 denotes a rotating image carrier type electrophotographic photosensitive member as an image carrier. The image carrier 1 in this example is a negatively charged organic photoconductor and is rotationally driven in a clockwise direction indicated by an arrow at a predetermined peripheral speed by a driving motor (not shown).

  The image carrier 1 is uniformly charged to a predetermined negative potential by a charging device during the rotation process. In this example, the charging device is a contact charging device using a charging roller 2 as a charging member. The charging roller 2 rotates following the image carrier 1. A bias voltage is applied to the charging roller 2 from a charging bias power source (not shown) to uniformly charge the image carrier.

  Next, image exposure by the exposure device 21 is performed. The exposure device 21 forms an electrostatic latent image on the uniformly charged image carrier 1, and a semiconductor laser scanner is used in this example. The exposure device 21 outputs a laser beam modulated in response to an image signal sent from a host device (not shown) in the image forming apparatus, and carries an image through an exposure window portion of a process cartridge described later. The uniformly charged surface of the body 1 is subjected to scanning exposure (image exposure). On the surface of the image carrier, an electrostatic latent image corresponding to image information is sequentially formed by making the absolute value of the potential at the exposed portion lower than the absolute value of the charged potential.

  Next, the electrostatic latent image is developed by the reversal developing device 5 to be visualized as a toner image. In this example, a jumping development method is used. In this method, a developing bias voltage in which alternating current and direct current are superimposed is applied to a developing sleeve 7 from a developing bias power source (not shown), and friction charging is performed at a contact portion between the developer layer thickness regulating member 6 and the developing sleeve 7. The negatively charged toner is applied to the electrostatic latent image on the surface of the image carrier to reversely develop the electrostatic latent image.

  The toner image on the surface of the image carrier is transferred by a transfer device to a recording medium (transfer material) such as paper fed from a paper supply unit (not shown). In this example, a contact transfer device using a transfer roller 22 is used. The transfer roller 22 is pressed against the image carrier 1 by an urging means such as a pressing spring (not shown) in the center direction of the image carrier. When the transfer material is conveyed and the transfer process is started, a positive transfer bias voltage is applied to the transfer roller 22 from a transfer bias power source (not shown), and the negatively charged image carrier 1 is charged. The toner is transferred onto the transfer material.

  The transfer material that has received the transfer of the toner image is separated from the surface of the image carrier and introduced into the fixing device 23 to undergo a fixing process of the toner image. The fixing device 23 fixes the toner image transferred onto the transfer material to a permanent image using means such as heat or pressure.

  The image carrier surface after separation of the transfer material is cleaned by scraping off the transfer residual toner by the cleaning device 4 and is repeatedly used for image formation. The cleaning device 4 of this example uses a cleaning blade 3. The cleaning blade 3 collects transfer residual toner that has not been completely transferred from the image carrier 1 to the transfer material during the transfer process. The cleaning blade 3 contacts the image carrier 1 with a constant pressure and collects the transfer residual toner. Clean the surface of the image carrier. After completion of the cleaning process, the surface of the image carrier again enters the charging process.

  The image forming apparatus forms an image by repeating the steps of charging, exposure, development, transfer, fixing, and cleaning using the above-described means.

  Here, the process cartridge is a cartridge in which a charging unit, a developing unit or a cleaning unit and an electrophotographic photosensitive member are integrally formed, and this cartridge can be attached to and detached from the image forming apparatus main body. In addition, at least one of the charging unit, the developing unit, and the cleaning unit and the electrophotographic photosensitive member are integrally formed into a cartridge that can be attached to and detached from the main body of the image forming apparatus. Further, it means that at least the developing means and the electrophotographic photosensitive member are integrated into a cartridge so that it can be attached to and detached from the apparatus main body.

  The cleaning blade of the present invention will be described.

  The cleaning means according to the present invention is a cleaning blade 3 integrally having an elastic blade made of polyurethane resin as shown in FIG. The residual toner after the transfer process is removed from the circumferential surface of the image carrier by bringing the tip of the elastic blade into contact with the circumferential surface of the image carrier with a predetermined pressing force in a so-called counter direction. .

  In order to obtain the effect of the present invention, the measured value of the hardness by a micro rubber hardness meter at the longitudinal ends of the front end surface of the cleaning blade is 72 ° to 90 ° (preferably 72 ° to 80 °), and the entire side surface And the hardness of the central portion in the longitudinal direction of the tip surface are preferably 55 ° or more and 70 ° or less (preferably 62 ° or more and 70 ° or less).

  When the hardness of both ends in the longitudinal direction of the front end surface of the cleaning blade is less than 72 °, the frictional force between the cleaning blade and the surface of the image carrier increases, and the blade is liable to chatter or sag.

  When the hardness at both ends in the longitudinal direction of the front end surface of the cleaning blade is greater than 90 °, the frictional force between the blade end and the image carrier surface becomes small, and toner leakage from the blade end tends to occur.

  When the hardness of the entire side surface of the cleaning blade and the hardness of the central portion in the longitudinal direction of the front end surface are less than 55 °, the frictional force between the surface of the image carrier and the surface of the image carrier increases, and chatter and blade deflection tend to occur.

  If the hardness of the entire side surface of the cleaning blade and the hardness of the central portion in the longitudinal direction of the tip surface are greater than 70 °, it becomes difficult to form a nip with the surface of the image carrier over the entire longitudinal direction, resulting in poor cleaning. May occur.

  The micro hardness is obtained by measuring the load when a needle having a diameter of 0.16 mm and a height of 0.5 mm is pressed against a rubber blade in an environment of a temperature of 23 ° C. and a humidity of 50% to determine the hardness of the surface portion of the blade. The measurement was performed using a micro hardness meter (MD-1 manufactured by Kobunshi Keiki Co., Ltd.). The measurement was performed with an average of 10 points.

  As shown in FIG. 4, the cleaning blade 3 was prepared by adjusting the hardness based on a blade shape (plate shape) having a rectangular shape as a whole. However, it is not limited to this shape.

  The positional relationship in the longitudinal direction of each component is shown in FIG. There is a printable area A that can be printed on a recording medium such as paper, and the toner coat area B is on the developing roller wider in the longitudinal direction than that in consideration of production play in the longitudinal direction. In order to prevent the toner from adhering to the image carrier outside the toner coat area, there is a charged area C wider than the toner coat area. Then, there was a cleaning blade that was sufficiently longer in the longitudinal direction than the charged region C, and an impregnation treatment using an isocyanate compound was performed on the end surface of the cleaning blade. Further, the respective longitudinal end portions are defined as a printable region end portion A ′, a toner coat region end portion B ′, and a charging region end portion C ′.

  As a means of surface treatment for curing both ends in the longitudinal direction of the front end surface of the cleaning blade, at least an area outside the printable area where the toner image can be printed on the longitudinal recording medium on the front end face is impregnated with an isocyanate compound. Or a method of applying a urethane resin.

  In particular, a method of impregnating with an isocyanate compound is preferably used, and a cleaning blade having a high treatment layer strength and good durability can be produced. Therefore, the effect of the present invention can be maintained even in long-term use.

  The method for impregnating the cleaning blade surface with an isocyanate compound is not particularly limited, but the following method is preferably used in the present invention.

  A solution containing an isocyanate compound is applied to the end of a cleaning blade made of polyurethane rubber. As a result, the isocyanate compound and the polyurethane resin gradually react to form a treatment layer having a low friction coefficient on the surface of the cleaning blade. Thereafter, the applied solution is wiped off using alcohol.

  The cleaning blade of the present invention is characterized in that the treatment portion swells when impregnated with an isocyanate compound. Generally, by curing the cleaning blade, the frictional force with the image carrier is reduced, and cleaning failure is likely to occur. In the isocyanate treatment of the present invention, the treated portion swells, so that the untreated portion can be brought into contact with the image carrier with a strong pressure. The effect can be sustained.

  As shown in FIG. 6, the cleaning blade edge on the image carrier contact surface side of the processing portion at the charged region end C ′, and the parallel extension line of the cleaning blade edge on the image carrier contact surface side of the unprocessed portion, Is the swelling height h. The swelling height h is preferably 30 μm or less (preferably 10 μm or more and 30 μm or less).

  When the swelling height h is less than 10 μm, the cleaning blade tends to chatter or sag.

  When the swelling height h is larger than 30 μm, cleaning failure is likely to occur.

  Further, the contact edge of the cleaning blade with the image carrier at the end position of the charged region end C ′ where the surface treatment is performed is parallel to the contact edge of the cleaning blade of the untreated part with the image carrier. A region where the width of the extension line is 10% to 90% is called a transition region. This transition area is preferably located outside the printable area where the toner image can be printed on the recording material and inside the toner coat area of the developer.

  When the transition area is located inside the printable area where the toner image can be printed on the recording material, an external additive having a particle diameter smaller than that of the toner slips out of the transition area w, contaminates the charging roller, and causes a charging failure. However, image defects may occur.

  When the transition area is located outside the toner coat area of the developer, blade chatter or wobbling may occur.

  As another means for curing both longitudinal ends of the front end surface of the cleaning blade, there is a method of applying a binder of urethane resin, silicone resin, or fluorine resin at a desired position.

  Examples of the binder resin used in the toner of the present invention include vinyl resins, polyester resins, epoxy resins, polyurethane resins, and the like, but are not particularly limited, and conventionally known resins can be used. Among them, it is preferable to contain a polyester resin because of good chargeability and quick rise, and sharp melt and particularly excellent low-temperature fixability. As the binder resin, these resins can be used alone or in combination of two or more.

  The composition of the polyester resin is as follows.

  Examples of the divalent alcohol component include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1, 6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, and bisphenol represented by the formula (A) and derivatives thereof;

（式中、Ｒはエチレン又はプロピレン基であり、ｘ，ｙはそれぞれ０以上の整数であり、かつ、ｘ＋ｙ平均値は０〜１０である。）
また（Ｂ）式で示されるジオール類；

(In the formula, R is an ethylene or propylene group, x and y are each an integer of 0 or more, and the average value of x + y is 0 to 10.)
And diols represented by the formula (B);

（ｘ’，ｙ’は０以上の整数であり、かつ、ｘ＋ｙの平均値は０〜１０である。）
が挙げられる。

(X ′ and y ′ are integers of 0 or more, and the average value of x + y is 0 to 10.)
Is mentioned.

  Examples of the divalent acid component include benzene dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and phthalic anhydride or anhydrides thereof, lower alkyl esters; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid. Acids or anhydrides thereof, lower alkyl esters; alkenyl succinic acids or alkyl succinic acids such as n-dodecenyl succinic acid and n-dodecyl succinic acid, or anhydrides, lower alkyl esters thereof; fumaric acid, maleic acid, citraconic acid, itaconic acid Dicarboxylic acids such as unsaturated dicarboxylic acids or anhydrides thereof, lower alkyl esters;

  Further, it is preferable to use a trivalent or higher alcohol component or a trivalent or higher acid component that acts as a crosslinking component alone or in combination.

  Examples of the trihydric or higher polyhydric alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butane. Triol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxybenzene, etc. Is mentioned.

  Examples of the trivalent or higher polycarboxylic acid component in the present invention include trimellitic acid, pyromellitic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5, 7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylene Carboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, empole trimer acid, and their anhydrides, lower alkyl esters;

（式中Ｘは炭素数３以上の側鎖を１個以上有する炭素数５乃至３０のアルキレン基又はアルケニレン基）
で表わされるテトラカルボン酸等、及びこれらの無水物、低級アルキルエステル等の多価カルボン酸類及びその誘導体が挙げられる。

(Wherein X is an alkylene group or alkenylene group having 5 to 30 carbon atoms having one or more side chains having 3 or more carbon atoms)
And polycarboxylic acids such as anhydrides and lower alkyl esters thereof and derivatives thereof.

  The alcohol component used in the present invention is 40 to 60 mol%, preferably 45 to 55 mol%, and the acid component is 60 to 40 mol%, preferably 55 to 45 mol%. The trivalent or higher polyvalent component is preferably 5 to 60 mol% in all components.

  The polyester resin is usually obtained by a generally known condensation polymerization.

  In the present invention, in addition to the polyester resin, the following vinyl resin may be used as the binder resin.

  Examples of vinyl resins include styrene; o-methylstyrene, m-methylstyrene, p-methylenestyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethyl. Styrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene , Styrene derivatives such as pn-dodecylstyrene; ethylene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; unsaturated polyenes such as butadiene; vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, etc. Of vinyl halides; vinyl acetate, vinyl propionate, benzo Vinyl esters such as vinyl acid; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, Α-methylene aliphatic monocarboxylic acid esters such as phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, acrylic Acrylic acid esters such as n-octyl acid, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; vinylmethyl Vinyl ethers such as ether, vinyl ethyl ether and vinyl isobutyl ether; Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone N-vinyl compounds such as; vinyl naphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, acrylamide; esters of α, β-unsaturated acids, diesters of dibasic acids; acrylic acid, methacrylic acid, Acrylic acid such as α-ethylacrylic acid, crotonic acid, cinnamic acid, vinyl acetic acid, isocrotonic acid, angelic acid and α- or β-alkyl derivatives thereof; fumaric acid, maleic acid, citraconic acid, alkenyl succinic acid, itaconic acid And polymers using vinyl monomers such as unsaturated dicarboxylic acids such as mesaconic acid, dimethylmaleic acid and dimethylfumaric acid, and monoester derivatives or anhydrides thereof. In the vinyl resin, vinyl monomers as described above are used alone or in combination of two or more. Among these, a combination of monomers that becomes a styrene copolymer or a styrene-acrylic copolymer is preferable.

  The method for synthesizing a binder resin composed of a vinyl-based homopolymer or copolymer is not particularly limited, and various conventionally known production methods can be used. For example, a bulk polymerization method, a solution polymerization method, Polymerization methods such as suspension polymerization and emulsion polymerization can be used. When a carboxylic acid monomer or an acid anhydride monomer is used, it is preferable to use a bulk polymerization method or a solution polymerization method because of the properties of the monomer.

  In addition, the binder resin used in the present invention may be a polymer or copolymer cross-linked with a cross-linkable monomer as exemplified below if necessary. As the crosslinkable monomer, a monomer having at least two crosslinkable unsaturated bonds can be used. As such a crosslinkable monomer, various monomers as shown below are conventionally known and can be suitably used for the developer of the present invention.

  Examples of the crosslinkable monomer include divinylbenzene and divinylnaphthalene as aromatic divinyl compounds; diacrylate compounds linked with an alkyl chain such as ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and those obtained by replacing acrylate of the above compounds with methacrylate; ether bond Examples of diacrylate compounds linked by an alkyl chain containing, for example, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol Coal # 400 diacrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate and the above compounds in which the acrylate is replaced with methacrylate; diacrylate compounds linked by a chain containing an aromatic group and an ether bond For example, polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane diacrylate, polyoxyethylene (4) -2,2-bis (4-hydroxyphenyl) propane diacrylate and the above The thing which replaced the acrylate of the compound with the methacrylate is mentioned; As a polyester type diacrylate, a brand name MANDA (Nippon Kayaku) etc. are mentioned, for example.

  Polyfunctional cross-linking agents include pentaerythritol triacrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate, and acrylates of the above compounds replaced with methacrylate; triallylcia Examples thereof include nurate and triallyl trimellitate.

  Among the above-mentioned crosslinkable monomers, aromatic divinyl compounds (particularly divinylbenzene), aromatic groups and ether bonds are preferred as binder resins from the viewpoint of fixability and offset resistance of the resulting toner. Examples include diacrylate compounds linked by a chain.

  Moreover, it is preferable to adjust the usage-amount of the said crosslinking agent by the kind of monomer which is going to bridge | crosslink, the physical property calculated | required by binder resin, etc. For example, the crosslinking agent is preferably used in an amount of 0.01 to 10 parts by weight, more preferably 0.03 to 5 parts by weight, with respect to 100 parts by weight of other monomer components that generally constitute the binder resin.

  In the present invention, a vinyl polymer homopolymer or copolymer other than the above, polyester, polyurethane, epoxy resin, polyvinyl butyral, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, Aromatic petroleum resin or the like can be used by mixing with the above-described binder resin as necessary. When two or more kinds of resins are mixed and used as the binder resin, it is more preferable to mix those having different molecular weights at an appropriate ratio.

  The binder resin used in the toner of the present invention preferably has a glass transition temperature (Tg) of 45 to 80 ° C., more preferably 50 to 70 ° C., from the viewpoints of storage stability and fixability.

  The measuring method of the glass transition temperature (Tg) of the binder resin is performed according to ASTM D3418-82 using Q-1000 manufactured by TA Instruments. The DSC curve used in the present invention is a DSC curve measured when the temperature is raised at a rate of 10 ° C./min after raising and lowering the temperature once and taking a previous history. In the DSC curve at the time of temperature increase obtained at this time, the temperature at the intersection of the line connecting the midpoint of the baseline before and after the change in specific heat and the DSC curve was defined as the glass transition temperature (Tg).

  The binder resin used in the toner of the present invention preferably has an acid value from the viewpoint of reducing environmental dependency. The acid value of the binder resin is preferably 1 to 50 mgKOH / g.

  The hydroxyl value of the binder resin used for the toner is preferably 60 mgKOH / g or less from the viewpoint of reducing the environmental dependency. The toner of the present invention may contain a wax.

  Examples of the wax used in the present invention include the following. Low molecular weight polyethylene, low molecular weight polypropylene, polyolefin copolymer, polyolefin wax, microcrystalline wax, paraffin wax, aliphatic hydrocarbon wax such as Fischer-Tropsch wax; oxide of aliphatic hydrocarbon wax such as oxidized polyethylene wax; Or block copolymers thereof; plant waxes such as candelilla wax, carnauba wax, wood wax, jojoba wax; animal waxes such as beeswax, lanolin, whale wax; mineral waxes such as ozokerite, ceresin, petrolactam A wax mainly composed of an aliphatic ester such as a montanic acid ester wax or a caster wax; a wax obtained by partially or fully deoxidizing an aliphatic ester such as a deoxidized carnauba wax. Further, saturated linear fatty acids such as palmitic acid, stearic acid, montanic acid, or long-chain alkyl carboxylic acids having a long-chain alkyl group; unsaturated fatty acids such as brassic acid, eleostearic acid, and valinal acid; stearyl alcohol Saturated alcohol such as eicosyl alcohol, behenyl alcohol, cannavir alcohol, seryl alcohol, melyl alcohol, or alkyl alcohol having a long chain alkyl group; polyhydric alcohol such as sorbitol; linoleic acid amide, oleic acid amide, lauric acid Aliphatic amides such as acid amides; saturated aliphatic bisamides such as methylene bisstearic acid amide, ethylene biscapric acid amides, ethylene bislauric acid amides, hexamethylene bisstearic acid amides; Unsaturated fatty acid amides such as inamide, hexamethylenebisoleic acid amide, N, N′-dioleyl adipic acid amide, N, N′-dioleyl sebacic acid amide; m-xylene bisstearic acid amide, N, Aromatic bisamides such as N'-distearylisophthalamide; aliphatic metal salts such as calcium stearate, calcium laurate, zinc stearate and magnesium stearate (commonly referred to as metal soap); aliphatic hydrocarbons Wax grafted with a vinyl monomer such as styrene or acrylic acid; Partial esterified product of fatty acid and polyhydric alcohol such as behenic acid monoglyceride; Hydroxyl group obtained by hydrogenating vegetable oil Methyl ester compound. Specific product names of the wax include the following. Biscol (registered trademark) 330-P, 550-P, 660-P, TS-200 (Sanyo Chemical Industries), High Wax 400P, 200P, 100P, 410P, 420P, 320P, 220P, 210P, 110P (Mitsui Chemicals) ), Sazole H1, H2, C80, C105, C77 (Schumann Sazol), HNP-1, HNP-3, HNP-9, HNP-10, HNP-11, HNP-12 (Nippon Seiki Co., Ltd.), Unilin (registered trademark) 350, 425, 550, 700, Unicid (registered trademark), Unicid (registered trademark) 350, 425, 550, 700 (Toyo Petrolite), wood wax, beeswax, rice wax, candelilla wax Carnauba wax (available from Celerica NODA).

  In addition, these waxes have a sharp molecular weight distribution using a press sweating method, a solvent method, a recrystallization method, a vacuum distillation method, a supercritical gas extraction method or a melt liquid crystal deposition method, a low molecular weight solid fatty acid, a low molecular weight A solid alcohol, a low molecular weight solid compound, and other impurities are preferably used.

  When the toner of the present invention is obtained, the use of a one-component developing method by incorporating a magnetic material into a one-component toner eliminates the need for a carrier, which is advantageous in terms of downsizing the apparatus.

  The following are mentioned as a magnetic material in this invention. Iron oxides such as magnetite, maghemite, ferrite; metals such as iron, cobalt, nickel or these metals aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, Alloys of metals such as selenium, titanium, tungsten, vanadium and mixtures thereof.

  These magnetic materials preferably have an average particle size of 2 μm or less, more preferably 0.05 μm or more and 0.5 μm or less. The amount of the magnetic material to be contained in the toner is preferably 20 to 200 parts by mass with respect to 100 parts by mass of the resin component, and more preferably 40 to 150 parts by mass with respect to 100 parts by mass of the resin component.

  The toner of the present invention preferably contains a charge control agent.

  Examples of the charge control agent for controlling the toner to be negatively charged include the following compounds.

  Organometallic complexes and chelate compounds are effective, and there are monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid metal complexes. Others include aromatic hydroxycarboxylic acids, aromatic mono and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol.

  Among these, an azo metal complex represented by the following general formula (1) or a basic organic acid metal complex represented by the following general formula (2) is preferable.

  In the above general formula (1), the coordination center metal M is particularly preferably Fe, the substituent is preferably a halogen, an alkyl group or an anilide group, and the counter ion is preferably hydrogen, an alkali metal, ammonium or aliphatic ammonium. . A mixture of complex salts having different counter ions is also preferably used.

  In the general formula (2), the coordination center metal M is particularly preferably Fe, Cr, Si, Zn or Al, and the substituent is preferably an alkyl group, anilide group, aryl group or halogen. The counter ion is preferably hydrogen, ammonium or aliphatic ammonium.

  Examples of the charge control agent for controlling the toner to be positively charged include the following compounds.

  Modified products with nigrosine and fatty acid metal salts; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and onium salts such as phosphonium salts thereof. And these lake pigments, triphenylmethane dyes and these lake pigments. Metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate, dioctyltin borate, dicyclohexyl Such diorgano tin borate of Suzuboreto; guanidine compounds, imidazole compounds. These can be used alone or in combination of two or more. Among these, triphenylmethane compounds and quaternary ammonium salts whose counter ions are not halogen are preferably used. The following general formula (3)

［式中、Ｒ₁はＨ又はＣＨ₃を示し、Ｒ₂及びＲ₃は置換又は未置換のアルキル基（好ましくはＣ₁〜Ｃ₄）を示す。］
で表わされるモノマーの単重合体；前述したスチレン、アクリル酸エステル、メタクリル酸エステルの如き重合性モノマーとの共重合体を正荷電性制御剤として用いることができる。この場合これらの荷電制御剤は、結着樹脂（の全部又は一部）としての作用をも有する。

[Wherein R ₁ represents H or CH ₃ , and R ₂ and R ₃ represent a substituted or unsubstituted alkyl group (preferably C _{1 to} C ₄ ). ]
A homopolymer of a monomer represented by the following: A copolymer with a polymerizable monomer such as styrene, acrylic acid ester or methacrylic acid ester described above can be used as a positive charge control agent. In this case, these charge control agents also have an action as a binder resin (all or a part thereof).

  In particular, a compound represented by the following general formula (4) is preferred as the positive charge control agent of the present invention.

  As a method for adding the charge control agent to the toner, there are a method of adding the toner inside the toner particles and a method of adding the toner outside the toner particles. The amount of use of these charge control agents is determined by the toner production method including the type of binder resin, the presence or absence of other additives, and the dispersion method, and is not uniquely limited. As a guide, the following amounts are preferable. That is, the charge control agent is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the binder resin.

  It is preferable that inorganic particles are externally added to the toner particles of the present invention. Examples of the inorganic fine particles include fine silica powder, fine titanium oxide powder, and hydrophobized products thereof. They are preferably used alone or in combination.

  Examples of the silica fine powder include both a dry process produced by vapor phase oxidation of a silicon halogen compound or dry silica called fumed silica, and wet silica produced from water glass or the like. Dry silica with fewer silanol groups on the surface and inside and no production residue is preferred.

  Further, the silica fine powder is preferably hydrophobized. The hydrophobizing treatment is applied by chemically treating with an organosilicon compound that reacts or physically adsorbs with silica fine powder. Preferable methods include a method in which a dry silica fine powder produced by vapor phase oxidation of a silicon halogen compound is treated with a silane compound or with a silane compound and simultaneously with an organosilicon compound such as silicone oil.

  The following are mentioned as a silane compound used for a hydrophobization process. Hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloro Ethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilane mercaptan, trimethylsilyl mercaptan, triorganosilyl acrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyl Disiloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane Siloxane.

Examples of the organosilicon compound include silicone oil. The silicone oil preferably has a viscosity at 25 ° C. of about 30 to 1,000 mm ² / s. Examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorophenyl silicone oil, and fluorine modified silicone oil.

  Silicone oil treatment can be performed by directly mixing silica powder treated with a silane compound and silicone oil using a mixer such as a Henschel mixer, or by spraying silicone oil onto the base silica. Also good. Alternatively, the silicone oil may be dissolved or dispersed in an appropriate solvent, and then mixed with the base silica fine powder to remove the solvent.

  As a preferable hydrophobizing treatment of the silica fine powder, there is a method of preparing by treating with hexamethyldisilazane and then treating with silicone oil.

  As described above, it is preferable to treat the silica fine powder with the silane compound and then oil-treat it later, so that the degree of hydrophobicity can be effectively increased.

  The silica fine powder is preferably subjected to a hydrophobization treatment, and further, an oil treatment applied to the titanium oxide fine powder, similarly to the silica-based one.

  To the toner particles of the present invention, additives other than silica fine powder or titanium oxide fine powder may be externally added as necessary.

  For example, charging aids, conductivity-imparting agents, fluidity-imparting agents, anti-caking agents, release agents at the time of heat roll fixing, resin fine particles or inorganic fine particles functioning as lubricants or abrasives can be mentioned.

  The fine resin particles preferably have an average particle size of 0.03 to 1.0 μm. Examples of the polymerizable monomer constituting the resin fine particles include the following. Styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-ethylstyrene derivatives; acrylic acid; methacrylic acid; methyl acrylate, ethyl acrylate, n-butyl acrylate, acrylic acid Acrylic esters such as isobutyl, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; methyl methacrylate, ethyl methacrylate , N-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, methacryl Dimethylaminoethyl, such as methacrylic acid esters of diethylaminoethyl methacrylate; acrylonitrile, methacrylonitrile, a monomer such as acrylamide.

  Examples of the polymerization method for producing resin fine particles from the polymerizable monomer include suspension polymerization, emulsion polymerization, and soap-free polymerization. More preferably, particles obtained by soap-free polymerization are good.

  Examples of other fine particles include the following.

  Lubricants such as poly (ethylene fluoride), zinc stearate and polyvinylidene fluoride (especially preferred is polyvinylidene fluoride); abrasives such as cerium oxide, silicon carbide and strontium titanate (especially preferred is strontium titanate); titanium oxide A fluidity-imparting agent such as aluminum oxide (in particular, a hydrophobic agent is preferred); an anti-caking agent; a conductivity-imparting agent such as carbon black, zinc oxide, antimony oxide, and tin oxide. Further, a small amount of white fine particles and black fine particles having a polarity opposite to that of the toner may be used as a developability improver.

  The inorganic fine particles contained in the toner preferably have 0.01 to 5 parts by mass, more preferably 0.01 to 3 parts by mass with respect to 100 parts by mass of the toner.

  The toner of the present invention can be produced by a known method. As a method for producing the toner of the present invention, the materials constituting the toner particles are sufficiently mixed by a ball mill or other mixer, then kneaded well using a heat kneader such as a hot roll kneader or an extruder, and after cooling and solidification. A method in which the toner is obtained by mechanically pulverizing and classifying the pulverized powder and then adding and mixing external additives is preferable.

  The equipment used for producing the toner of the present invention is not particularly limited, and examples thereof include the following.

  Henschel mixer (made by Mitsui Mining); Super mixer (made by Kawata); Ribocorn (made by Okawara Seisakusho); Nauter mixer, turbulizer, cyclomix (made by Hosokawa Micron); Spiral pin mixer ( Pacific Kiko Co., Ltd.); Redige mixer (Matsubo Co., Ltd.).

  As a kneading machine, for example, KRC kneader (manufactured by Kurimoto Iron Works); Bus co-kneader (manufactured by Buss); TEM type extruder (manufactured by Toshiba Machine); TEX twin-screw kneader (manufactured by Nippon Steel Works) PCM kneading machine (Ikegai Iron Works); Three roll mill, mixing roll mill, kneader (Inoue Seisakusho); Needex (Mitsui Mining); MS pressure kneader, Nider Ruder (Moriyama Seisakusho) A Banbury mixer (manufactured by Kobe Steel).

  Examples of the pulverizer include an inomizer (manufactured by Hosokawa Micron); a kryptron (manufactured by Kawasaki Heavy Industries); a turbo mill (manufactured by Turbo Industry); and a super rotor (manufactured by Nisshin Engineering).

  Classifiers include, for example, a class seal, a micron classifier, a speck classifier (manufactured by Seishin Enterprise); a turbo classifier (manufactured by Nisshin Engineering); a micron separator, a turboplex (ATP), a TSP separator (manufactured by Hosokawa Micron) ); Elbow Jet (manufactured by Nippon Steel Mining Co., Ltd.), Dispersion Separator (manufactured by Nippon Pneumatic Industrial Co., Ltd.); YM Microcut (manufactured by Yaskawa Shoji Co., Ltd.).

  Examples of sieving devices used to screen coarse particles include Ultrasonic (manufactured by Sakae Sangyo Co., Ltd.); Resonator Sheave, Gyroshifter (Tokuju Kosakusha Co., Ltd.); Vibrasonic System (Dalton Co., Ltd.); Examples include a turbo screener (manufactured by Turbo Industry Co., Ltd.), a micro shifter (manufactured by Kanno Sangyo Co., Ltd.), and a circular vibrating sieve.

  Next, a method for producing toner particles using a surface modification step, which is a preferred method for obtaining the toner particles of the present invention, will be described.

  Examples of the surface modification apparatus include those shown below. Faculty (manufactured by Hosokawa Micron), Mechano-Fusion (manufactured by Hosokawa Micron), Nobilta (manufactured by Hosokawa Micron), Hybridizer (manufactured by Nara Machinery), Inomizer (manufactured by Hosokawa Micron), Mechano mill (Okada Seiko Co., Ltd.), Cryptron (Kawasaki Heavy Industries Co., Ltd.), Super Rotor (Nisshin Engineering Co., Ltd.), Turbo Mill (Turbo Industry Co., Ltd.), Tornado Mill (Nikkiso Co., Ltd.). A pulverizer or the like can also be used as the toner particle surface modifying apparatus of the present invention. In the surface modification of the toner particles, the treatment may be repeated twice or more with the same apparatus, or two or more kinds of surface modification apparatuses may be combined.

  In the surface modification apparatus, for example, Faculty (manufactured by Hosokawa Micron Corporation) has a function of removing fine powder components simultaneously with the surface modification of toner particles in the toner particle surface modification step. When using a surface modification device that can remove fine powder components at the same time as the surface modification of toner particles in this way, the raw material toner particles finely divided in the vicinity of a desired particle size are converted into fine powder and coarse particles using an airflow classifier. It is preferable to perform surface modification after removing the powder to some extent. In this case, the toner particles from which fine powder has been removed by the airflow classifier have a cumulative value of the number average distribution of toner particles of less than 4 μm in a particle size distribution measured using a Coulter counter method of 10% or more and less than 50%. Preferably, it is 15% or more and less than 45%, more preferably 15% or more and less than 30%. Setting the cumulative value of the number average distribution of toner particles of less than 4 μm in the classification step to less than 10% is not practical because the toner productivity is significantly reduced. On the other hand, if it is 50% or more, the surface modification tends to be non-uniform, and the desired toner fluidity of the present invention is difficult to obtain. Examples of the airflow classifier used in the present invention include elbow jet (manufactured by Nippon Steel Industries Co., Ltd.).

  The present invention is characterized in that in the toner particle surface modification step, the fine powder component can be removed simultaneously with the toner particle surface modification. By modifying the surface of the toner particles, the cohesive force between the toners is reduced. Furthermore, by removing the fine powder component, the ultrafine particles present in the toner particles are less likely to adhere to the surface of the toner particles, so that the fluidity of the toner is less likely to be hindered. As a result, a toner having desired E, E-Ea, and Ed / E values can be effectively obtained. If the toner particles have low smoothness or if the toner particles contain a large amount of ultrafine particles, the fluidity between the toners decreases, and the values of E, E-Ea, and Ed / E necessary for the present invention are reduced. It is difficult to obtain.

  In the present invention, “removing the fine powder component simultaneously with the surface modification” means that the surface modification of the toner particles and the removal of the fine powder are repeatedly performed. An apparatus having processes may be used, or surface modification and fine powder removal may be performed by different apparatuses, and each process may be repeated.

  Hereinafter, the present invention will be described with reference to specific examples, but the present invention is not limited thereto.

  The cleaning blade used in this example was the same shape as that used in the cartridge for the laser beam printer Laser Jet 4350n manufactured by Hewlett-Packard, and was subjected to a curing treatment as necessary. The production method is shown below (Table 1).

(Manufacturing example 1 of a cleaning blade)
A solution containing an isocyanate compound is applied to both ends of the cleaning blade made of polyurethane rubber having a hardness in the longitudinal direction of the tip surface of 66 ° and the hardness of the entire side surface of 64 ° (each 15 mm region). A cured layer was formed on the blade surface by reacting the compound and the polyurethane resin. The hardness of the treated part was 76 °. The swelling height h was 25 μm, and the position of the transition area was outside the printable area where the toner image can be printed on the recording material and inside the toner coat area of the developer.

(Manufacturing example 2 of cleaning blade)
A solution containing an isocyanate compound is applied to both ends of the cleaning blade made of polyurethane rubber having a hardness in the longitudinal direction of the tip surface of 66 ° and the hardness of the entire side surface of 64 ° (each 15 mm region). A cured layer was formed on the blade surface by reacting the compound and the polyurethane resin. The hardness of the treated part was 85 °. The swelling height h was 8 μm, and the position of the transition area was outside the printable area where the toner image can be printed on the recording material and inside the toner coat area of the developer.

(Manufacturing example 3 of the cleaning blade)
Hardening the blade surface by applying urethane resin to both ends of the cleaning blade made of polyurethane rubber with a hardness of 60 ° in the longitudinal direction of the tip surface and a hardness of 59 ° throughout the side surface (15 mm each). A layer was formed. The hardness of the treated part was 87 °. The swelling height h was 8 μm, and the position of the transition area was outside the printable area where the toner image can be printed on the recording material and inside the toner coat area of the developer.

(Manufacturing example 4 of cleaning blade)
Hardening the blade surface by applying urethane resin to both ends of the cleaning blade made of polyurethane rubber with a hardness of 60 ° in the longitudinal direction of the tip surface and a hardness of 59 ° throughout the side surface (each 19 mm area) A layer was formed. The hardness of the treated part was 88 °. The swelling height h was 40 μm, and the position of the transition area was inside the printable area where the toner image can be printed on the recording material.

(Manufacturing Example 5 of Cleaning Blade)
Hardening the blade surface by applying urethane resin to both ends of the cleaning blade made of polyurethane rubber with a hardness of 57 ° in the longitudinal direction of the tip surface and a hardness of 57 ° on the entire side surface (each 8 mm area) A layer was formed. The hardness of the treated part was 92 °. The swelling height h was 40 μm, and the position of the transition area was outside the toner coat area of the developer.

(Manufacturing Example 6 of Cleaning Blade)
A cleaning blade made of polyurethane rubber having a hardness of 54 ° in the longitudinal direction of the front end surface and a hardness of 54 ° in the entire side surface was used, and both ends were not treated.

(Manufacturing Example 7 of Cleaning Blade)
A hardened layer was formed on the blade surface by applying urethane resin to the entire tip surface of the cleaning blade made of polyurethane rubber having a hardness in the longitudinal direction of the tip surface of 60 ° and a hardness of the entire side surface of 60 °. The hardness of the processing part was 101 °. The swelling height h is 50 μm, and there is no transition region because the entire tip surface is processed.

  Table 2 shows the physical properties of the binder resin used in this example.

  The production method of the toner used in this example is shown below.

(Toner Production Example 1)
Binder resin 1: 100 parts by mass Wax: 3 parts by mass (low molecular weight polyethylene, DSC endothermic peak temperature = 102 ° C., Mn = 850)
Magnetite (average particle size 0.18 μm) 95 parts by mass Charge control agent (T-77 manufactured by Hodogaya Chemical Co., Ltd.): 2 parts by mass The above mixture was premixed with a Henschel mixer and then heated to 110 ° C. The kneaded material was melt-kneaded with an extruder, and the cooled kneaded material was coarsely pulverized with a hammer mill to obtain a coarsely pulverized toner product. The obtained coarsely pulverized product was coated with a mechanical pulverizer turbo mill (manufactured by Turbo Kogyo Co., Ltd .; coated with chromium alloy plating containing chromium carbide on the rotor and stator surfaces (plating thickness 150 μm, surface hardness HV1050)). Based on the condition table of Table 3, the air temperature at the inlet and outlet is adjusted and mechanically pulverized to finely pulverize. The resulting finely pulverized product is a multi-division classifier using the Coanda effect (Nittetsu Mining Co. Fine powder and coarse powder were simultaneously classified and removed by an elbow jet classifier. The weight average particle diameter (D4) measured by the Coulter counter method of the obtained raw material toner particles was 5.9 μm, and the cumulative value of the number average distribution of toner particles of less than 4 μm was 23.6%.

  The raw toner particles were subjected to surface modification and fine powder removal using a surface modification device faculty (manufactured by Hosokawa Micron). At that time, the rotational peripheral speed of the dispersion rotor is 150 m / sec, the input amount of the finely pulverized product is 7.6 kg per cycle, and the surface modification time (= cycle time, the discharge valve opens after the raw material supply is completed) Time) was 82 sec. The temperature when discharging the toner particles was 32 ° C. Through the above steps, negatively chargeable toner particles 1 were obtained. The physical properties of the toner particles 1 are shown in Table 2. Toner 1 was obtained by adding 1.3 parts by mass of hydrophobic silica to 100 parts by mass of the toner particles with a Henschel mixer.

  Table 3 shows values of E, E-Ea, and Ed / E measured by FT-4 of this toner 1. The weight average particle diameter (D4) of the toner 1 was 5.9 μm, and the cumulative value of the number average distribution of toners less than 4 μm was 21.3%.

(Toner Production Example 2)
Binder resin 1: 100 parts by mass Wax: 3 parts by mass (low molecular weight polyethylene, DSC endothermic peak temperature = 102 ° C., Mn = 850)
Magnetite (average particle size 0.18 μm) 95 parts by mass Charge control agent (T-77 manufactured by Hodogaya Chemical Co., Ltd.): 2 parts by mass In the same manner as in Toner Production Example 1, the above mixture was premixed, melt-kneaded, and coarse The toner was pulverized to obtain a coarsely pulverized toner. The obtained coarsely pulverized product was pulverized by mechanical pulverization by adjusting the air temperature at the inlet and outlet using a mechanical pulverizer turbo mill and adjusting the air temperature at the inlet and the outlet. The fine and coarse powders were classified and removed from the pulverized product at the same time. The weight average particle diameter (D4) measured by the Coulter counter method of the obtained raw material toner particles was 6.0 μm, and the cumulative value of the number average distribution of toner particles less than 4 μm was 24.3%.

  The raw toner particles were subjected to surface modification and fine powder removal using a surface modification device faculty. At that time, the rotational speed of the dispersion rotor was 130 m / sec, the amount of finely pulverized product was 7.6 kg per cycle, and the surface modification time was 82 sec. The temperature when discharging the toner particles was 30 ° C. Through the above steps, negatively chargeable toner particles 2 were obtained. Toner 2 was obtained by adding 1.3 parts by mass of hydrophobic silica to 100 parts by mass of the toner particles with a Henschel mixer. Table 3 shows the weight average particle diameter (D4) of this toner 2, the cumulative value of the number average distribution of toners less than 4 μm, and the values of E, E-Ea, and Ed / E measured by FT-4.

(Toner Production Example 3)
-Binder resin 2: 100 parts by mass-Wax: 3 parts by mass (low molecular weight polyethylene, DSC endothermic peak temperature = 102 ° C, Mn = 850)
Magnetite (average particle size 0.18 μm) 95 parts by mass Charge control agent (T-77 manufactured by Hodogaya Chemical Co., Ltd.): 2 parts by mass In the same manner as in Toner Production Example 1, the above mixture was premixed, melt-kneaded, and coarse The toner was pulverized to obtain a coarsely pulverized toner. The obtained coarsely pulverized product was pulverized by mechanical pulverization by adjusting the air temperature at the inlet and outlet using a mechanical pulverizer turbo mill and adjusting the air temperature at the inlet and the outlet. The fine and coarse powders were classified and removed from the pulverized product at the same time. The weight average particle diameter (D4) measured by the Coulter counter method of the obtained raw material toner particles was 6.6 μm, and the cumulative value of the number average distribution of toner particles less than 4 μm was 22.0%.

  The raw toner particles were subjected to surface modification and fine powder removal using a surface modification device faculty. At that time, the rotational speed of the dispersion rotor was 150 m / sec, the amount of finely pulverized product was 8.5 kg per cycle, and the surface modification time was 82 sec. The temperature when discharging the toner particles was 30 ° C. Through the above steps, negatively chargeable toner particles 3 were obtained. Toner 3 was obtained by adding 1.3 parts by mass of hydrophobic silica to 100 parts by mass of the toner particles with a Henschel mixer. Table 3 shows the weight average particle diameter (D4) of this toner 3, the cumulative value of the number average distribution of toners less than 4 μm, and the values of E, E-Ea, and Ed / E measured by FT-4.

(Toner Production Example 4)
-Binder resin 2: 100 parts by mass-Wax: 3 parts by mass (low molecular weight polyethylene, DSC endothermic peak temperature = 102 ° C, Mn = 850)
Magnetite (average particle size 0.18 μm) 95 parts by mass Charge control agent (T-77 manufactured by Hodogaya Chemical Co., Ltd.): 2 parts by mass In the same manner as in Toner Production Example 1, the above mixture was premixed, melt-kneaded, and coarse The toner was pulverized to obtain a coarsely pulverized toner. The obtained coarsely pulverized product was pulverized by mechanical pulverization by adjusting the air temperature at the inlet and outlet using a mechanical pulverizer turbo mill and adjusting the air temperature at the inlet and the outlet. The fine and coarse powders were classified and removed from the pulverized product at the same time. Through the above steps, negatively chargeable toner particles 4 were obtained. The weight average particle diameter (D4) measured by the Coulter counter method of the raw material toner particles thus obtained was 6.9 μm, and the cumulative value of the number average distribution of toner particles less than 4 μm was 20.3%. Toner 4 was obtained by adding 1.3 parts by mass of hydrophobic silica to 100 parts by mass of the toner particles with a Henschel mixer. Table 3 shows the weight average particle diameter (D4) of this toner 4, the cumulative value of the number average distribution of toners less than 4 μm, and the values of E, E-Ea, and Ed / E measured by FT-4.

(Toner Production Example 5)
-Binder resin 2: 100 parts by mass-Wax: 3 parts by mass (low molecular weight polyethylene, DSC endothermic peak temperature = 102 ° C, Mn = 850)
Magnetite (average particle size 0.18 μm) 95 parts by mass Charge control agent (T-77 manufactured by Hodogaya Chemical Co., Ltd.): 2 parts by mass Binder resin 2 was used in place of binder resin 1, and a mechanical grinder was used. Finely pulverize using a jet stream crusher IDS type mill (manufactured by Nippon Pneumatic Kogyo Co., Ltd.), change the classification conditions in the multi-division classifier, and do not modify the surface with a surface reformer Except for the above, toner particles 5 were obtained in the same manner as toner 1. Table 2 shows the physical properties of the toner particles 5. Toner 5 was obtained by adding 1.5 parts by mass of hydrophobic silica to 100 parts by mass of the toner particles with a Henschel mixer. Table 3 shows the physical properties of this toner 5 and the values of E, E-Ea, and Ed / E measured by FT-4. The cumulative value of the number average distribution of toner particles having a weight average particle diameter (D4) of the toner 5 of 5.8 μm and less than 4 μm was 25.1%.

[Examples 1 to 6, Comparative Examples 1 to 4]
Next, evaluation was performed by using the toners 1 to 5 prepared as described above by the following method. Table 4 shows the configuration of the toner and the cleaning blade used, and the evaluation results.

  A laser beam printer Laser Jet4350n manufactured by Hewlett-Packard Co. was modified to obtain an A4 size of 67 sheets / minute, and the following evaluation was performed.

(1) Image density In a high-temperature, high-humidity environment (32.5 ° C, 88% RH), the horizontal line pattern with a printing rate of 2% is set to 1 sheet / job, and the machine is temporarily stopped between jobs. In a mode in which the next job is set to start, a total of 18000 print-out tests were performed, and the image density at the initial stage and 18000 sheets was measured.

  For the image density, a “Macbeth reflection densitometer” (manufactured by Macbeth) was used to measure a relative density with respect to a printout image of a white background portion having an original density of 0.00.

(2) Blade chattering and dripping Under a high-temperature and high-humidity (32.5 ° C / 88%) environment, the horizontal line pattern with a printing rate of 2% is set to 1 sheet / job, and the machine temporarily stops between jobs. In a mode set so that the next job starts after that, a total of 18,000 image output tests were conducted, and the chattering and wobbling of the cleaning blade were observed when the photosensitive member was rotated and stopped.

The chattering and dripping of the cleaning blade were evaluated according to the following evaluation items.
A: There is no chattering or twisting of the blade.
B: When the blade was rotated and stopped, no chattering occurred but slight chattering occurred.
C: Chattering and wobbling are noticeable when the blade rotates and stops.
D: Practical use is difficult due to frequent chattering and wobbling during blade rotation and stoppage.

(3) Cover In a low-temperature, low-humidity environment (15 ° C, 10% RH), the horizontal line pattern with a print rate of 2% is set to 1 sheet / job, and the next job after the machine stops between jobs. In a mode set to start, a total of 18,000 image-drawing tests were conducted, and fogging at the initial stage and after 18,000 sheets was measured.

  The image quality of the fog was evaluated on the white background on the test chart. The fog was evaluated by calculating the fog density (%) from the difference between the whiteness of the white portion of the fixed image measured by a reflectometer (manufactured by Tokyo Denshoku) and the whiteness of the transfer material to evaluate the fog.

Unused paper reflectance-Image white area reflectance = Fog%
(4) Toner leakage / scattering In a high-temperature, high-humidity (32.5 ° C / 88%) environment, the horizontal line pattern with a printing rate of 2% is set to 1 sheet / job, and the machine temporarily stops between jobs. In the mode set so that the next job starts after that, a total of 18,000 image output tests were conducted, and the scattering level was evaluated according to the following criteria.
A: Toner leakage and scattering are hardly seen.
B: Slight toner leakage / scattering, but slightly adhered to the edge of the photoreceptor.
C: Toner leakage and scattering are conspicuous, adhere to the edge of the photoreceptor, and slightly stain the image.
D: Toner leakage / scattering is severe and drops on the image to make the image dirty and practically difficult to use.

(5) Slip-through In a low-temperature and low-humidity environment (15 ° C, 10% RH), the horizontal line pattern with a printing rate of 2% is set to 1 sheet / job. In the mode set to start, a total of 18,000 image drawing tests were conducted, and the slip-through level was evaluated according to the following criteria.
A: Almost no slip-through is seen.
B: There is no effect on the image although it is slightly worn.
C: There is a slight slip-through, but the charging means is slightly soiled and is not noticeable in the output image.
D: Slip through is bad and the image is stained.

It is explanatory drawing of a 48 mm diameter propeller type blade only for FT-4 measurement. 1 is a configuration diagram of an image forming apparatus. This is the positional relationship between the cleaning blade and the image carrier. It is a schematic diagram for demonstrating the cleaning blade of this invention. This is the longitudinal positional relationship of the process cartridge configuration. It is a schematic diagram for demonstrating the hardening process of the cleaning blade of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image carrier 2 Charging roller 3 Cleaning blade 4 Cleaning device 5 Developing device 6 Developer layer thickness regulating member 7 Developing sleeve 21 Exposure device 22 Transfer roller 23 Fixing device

Claims (3)

A charging step of charging the image carrier with a charging member; an electrostatic latent image forming step of forming an electrostatic charge image on the charged image carrier; and a toner image obtained by developing the electrostatic charge image with toner on the developing member. A developing step for forming the toner image, a transfer step for transferring the toner image formed on the image carrier onto the recording medium, and a surface of the image carrier after the transfer is brought into contact with a cleaning blade so that the image is carried by the edge portion. An image forming method having at least a cleaning step of removing transfer residual toner remaining on the body from the image carrier,
The measurement value of the hardness by the micro rubber hardness tester at both ends in the longitudinal direction of the tip surface of the cleaning blade is 72 ° or more and 90 ° or less, the hardness of the entire side surface, and the hardness of the center portion in the longitudinal direction of the tip surface is 55 ° or more and 70 °. And
The toner has toner particles containing at least a binder resin and a colorant, and inorganic fine particles, and has the following formulas (1) and (2):
600 (mJ) ≦ E ≦ 1500 (mJ) (1)
500 (mJ) ≦ (E−Ea) (2)
(In the formulas (1) and (2), E (mJ) vertically enters the toner powder layer in the container while rotating the peripheral speed of the outermost edge of the propeller blade at 100 mm / sec. The measurement starts from a position 100 mm from the bottom surface of the toner powder layer, and represents the sum of the rotational torque and the vertical load obtained when entering the position 10 mm from the bottom surface. Ea (mJ) is porous at the bottom of the container. (This represents the sum of the rotational torque and the vertical load in a ventilation state in which dry air with a flow rate of 0.20 mm / sec is sent from a material board.)
An image forming method characterized by satisfying The toner has the following formula (3)
0.10 ≦ (Ed / E) ≦ 0.70 (3)
(In the formula (3), Ed (mJ) is measured in the same manner as E (mJ) after stopping aeration from the state where dry air whose flow rate is controlled is being sent into the powder phase of the toner in the container. This represents the sum of the rotational torque and vertical load obtained in step 1).
The image forming method according to claim 1, wherein: 2. The cleaning blade according to claim 1, wherein at least a region outside a printable region where a toner image can be printed on a longitudinal recording medium on a front end surface is subjected to a surface treatment impregnated with an isocyanate compound. 3. The image forming method according to 1 or 2.

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